outer e^-

 1) completely gain or lose e^-

+cations

-electrons

2)share e^-

lose 1-3e^-

go back to Noble Gas conf.

Takes on charge

cations

gain 1-3 e^-

go to next Noble Gas conf.

takes on charge

anions -, -2, -3

show how atoms are joined

show unshared e-

show charge, if any 

attempt to describe true nature of bonding-usually with multiple bonds

rules:

correct #e-

obey rules of bonding

atoms NOT moved

ability of an atom in a bond to attract e- toward it

increase left-right

increase top-bottom

geometry of molecules

(figuring out)

1. draw lewis structure

2. count total # "things" attached to central atom

1) polarity of bonds

=polarity of

molecules

2) Geometry of molecules 

nonpolar

-a group of covalently bound atoms which have no charge

-complex ions

-nonmetals

-need to recognize type of compound

ionic and "mixed" 

(with polyatomic ions)

nomenclature

types

metal

ionic

one charge

Group 1,2,3

name metal then metal with -ide ending

nomenclature

types

nonmetal

ionic, covalent

binary (2 elements)

w/ polyatomic ions

metal name (roman numeral) nonmetal-ide

lower charge=ous

higher charge= ic

NaCN

=

Na+CN-

=

sodium cyanide

nonmetal+nonmetal

(molecules) share electrons

write and name "most metal-like" 1st

(least electronegative)

name 1st nonmetal 1st

if>1 give prefix

2nd one 2nd (-ide)

give prefix

di tri tetra penta hexa hepa octa nona deca

(reactants)    (products)

A+B yields C+D

balance!!! need to have the same number of each element on either side of equation

1. subscripts of compounds are fixed. do not change them when balancing equation

2. coefficients miust be in smalles whole number ration

3. coefficients multiply all numbers in formula

1. do atoms other than H&O first

- compound with most atoms first

-if polyatomic ion is unchanged, treat as one unit

2. do rest of atoms except H&O

3. do H&O- choose the one in fewest compounds first

4. check balance- if any fractions were used, multiply through to get whole numbers